The present disclosure relates to a pressing tool for the pressing-together of workpieces. More particularly, the present disclosure relates to a workpiece such as a fitting with an inserted pipe end, the pressure tool having at least two pressing jaws which are hinged to one another for enclosing the workpiece, and a hinge axis is arranged opposite an opening area of the pressing jaws.
From German Patent Document DE 42 40 427, a pressing tool with several pressing jaw elements is known, which are hinged to one another and, in an opening area, can be pulled together by a pressing jaw in order to press a workpiece received in the pressing jaw elements. In this case, an opening gap is necessarily provided between adjacent pressing jaw elements, in which the material to be pressed may be squeezed to the outside and will form wrinkles. Specifically in the pressing plane, a plane perpendicular to the pressing force of the jointing clamp, pressing forces can be transmitted only poorly to the workpiece.
Furthermore, a pressing tool is known from European Patent Document EP 1 095 739 which has only two pressing jaws which are hinged to one another by a pin. On the side situated opposite the pin, an opening gap is constructed which is closed during the pressing. The risk also exists here that, during the pressing-together, a wrinkle can form in the opening gap because of the lack of a pressing in the radial direction.
The present disclosure relates to providing a pressing tool having pressing forces that can be applied in a uniform manner and a formation of wrinkles in an opening area is avoided.
According to the present disclosure, a pressing element is disposed on a hinge pin, which pressing element can be moved toward a workpiece when the pressing jaws are closed. The pressing element presses the workpiece during a pressing-together in a direction of a opening area of the pressing jaws. As a result of counterforces occurring there, forces for the pressing-together of the workpiece exist on all sides. The pressing element is first arranged in a slightly withdrawn position before the pressing-together and, when the pressing jaws are closed, the workpiece can first be pressed in a direction of the hinge pin in order to first slightly close the pressing jaws. However, in a next phase, pressing forces are then also applied in an area of a pressing plane between the opening area and the hinge pin. By a uniform pressing-together of the workpiece, it may become possible to avoid a wrinkle formation in the area of the opening because, in this area, pressing forces are applied only when the pressing jaws are largely closed.
According to an embodiment of the present disclosure, the pressing element has wedge surfaces on a side facing the pressing jaws, to which wedge surfaces pressure surfaces of the pressing jaws are applied during the pressing-together of the workpiece. Therefore, as a result of the closing movement of the pressing jaws, the pressing element can be moved in the radial direction to the workpiece. By a selection of an angle of the wedge surfaces, a moving path of the pressing element during the closing movement of the pressing jaws can be defined. Thus, a corresponding intensification of force can be achieved.
As disclosed herein, two pressing jaws are provided which can be rotated about a hinge constructed as a pin. However, it is conceivable to mutually connect in a hinged manner more than two pressing jaws in order to implement a pressing-together by a wrap-around ring. The providing of only two pressing jaws means that only a few components are required for the pressing tool. Thus, the pressing element can have a leg with an oblong hole, and the pin can reach through this oblong hole. This is a simple way of displaceably fixing the pressing element. For an exact guidance of the pressing element, two legs can reach around the pressing jaws in a U-shaped manner.
In order to be able to apply pressing forces in the area of the pressing plane, the pressing jaws have projections adjacent to the opening area, which projections mesh with one another in a comb-type manner when the pressing jaws are closed. A recess on an opposite pressing jaw can be assigned to each projection of a pressing jaw. Although, in the opening area, a gap should still be formed between the pressing jaws before the pressing-together. This gap would no longer extend over an entire width of the pressing jaws but would be divided by the projections into several smaller sections. As a result, a risk of a wrinkle formation in the area between the pressing jaws may be avoided because the individual projections support the workpiece in this area.
Other aspects of the present disclosure will become apparent from the following descriptions when considered in conjunction with the accompanying drawings.